The present invention relates to an abnormal temperature detector for an electronic apparatus.
Electronic equipment such as a data processor is designed such that a plurality of wiring boards having IC elements mounted thereon are housed in a rack. The IC elements are cooled by forced convection of air using cooling fans to prevent a rise in temperature of each element and to maintain reliability.
In order to prevent a breakdown of such an apparatus, which is caused by a rise in temperature of the IC elements upon failure of the cooling fans or the like, the following method is employed. A detector is used to detect an atmospheric temperature near the rack. Upon detection of a temperature higher than a predetermined temperature, the detector sends a signal to a power supply circuit to stop the supply of power to the apparatus, thus protecting it.
FIG. 4 shows a conventional abnormal temperature detector.
Referring to FIG. 4, reference numeral 101 denotes a rack for housing wiring boards having IC elements mounted thereon; 102, a cooling fan; 103, a thermostat designed to open a contact at a preset temperature or more; 104, an abnormality detector; and 105, a power supply controller.
When a temperature near the rack 101 is increased to the preset temperature or more upon failure of the cooling fans 102 or the like, the contacts of the thermostats 103 are opened. The abnormality detector 104 detects this state and outputs a signal to the power supply controller 105 to stop the supply of power to the apparatus.
According to the above-described conventional abnormal temperature detector for electronic equipment, however, when the contacts are opened upon failure of the thermostats, or cables for connecting the thermostats to the power supply controller are disconnected, an abnormal temperature is erroneously detected to cause the power supply controller 105 to stop the supply of power to the apparatus.